Dumping mechanism for mechanical stokers



Patented .Dea e, 1927.

UNITED JSTATES PATENT foFFlciaz.

ROBERT' S. RILEY, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR TO IIItIIlEY,v STOKER CORPORATION, OF WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHU- SETTS.

DUMII'JSTGA MECHANISM FOR lIli'lECI-IAN'ICAL STOKERS.

Application medvxanuary 2a, 1924. serial No. 688,063.

This invention relates to a mechanical Stoker and particularly to mechanism for supporting and discharging the ash and refuse'thereof. lMy invention is particularly applicable to an underfeed Stoker and h as for its general object the prevention of discharge or rearward movement of the fuel from the retorts during the. discharge of refuse from the dumping plates.

-In the preferred construction, the stoker is provided with pivotally mounted movable overfeed grates at the rear ends of the retorts, said grates preferably h avlng a normal reciprocating movement with the retort side walls and receiving also an upward displacement as the dumping plates are swung downward. l AMy invention further relates to the provision of improved mechanism for attaining this desired result, together with other arl rangements and combinations of arts which will be hereinafter described an lmore particularly pointedv out in the appended claims.

A preferred form of the inventlon is shown inthe drawings, in which 4 Fig. 1 is a plan vlew of a portion of an underfeed stoker and its associated dumping plates;

Fig. 2 is a the stoker, ta Fig. 1;

Fig. 3 is a plan view of ing plates; and

ig. 4; is a partial sectional elevation of a modification.

Referrinfr `to the drawings, I have indicated certain parts of an underfeed Stoker 3o partial sectional elevation of en along the line 2-2 in lone of the dumpincluding a retort bottom plate 10 and re' tort side walls 11, each supporting a series or tuyre plates 12. A seriesof overfeed grates 13 are pivotally connected to the rear portions of the retort side walls 11 and are movable forward and rearward therewith.

The mechanism for moving the retort walls is not shown therein but may be similar to that shown in applicants prior Patent No. 1,090,651.

' The grates 13 are preferably 4of hollow construction, each grate whlch receives air from a cha-m. ber 15 which extends transversely across the stoker. The chamber-@1,5m receives air through a passage 16 from .a main air champroviding an air space 14 in' ber 17, and a. damper 18 between the chalnbers 15 and 17 permits regulation of the air pressure in the chamber 15.

The fuel supporting face of each grate 13 is preferably formed in a series of steps, with interposed air passages through whlch air from the chamber 15 is delivered to the fuel ou the overfeed grates. Lugs or projections 20are secured to the lower sides of the grates 13 and rest upon the 4upper surfaces of dumping plates 2l.

The dumping plates 21 are secured to a shaft 2,2 which extends transversel across the stoker and is supported in rigid earings 23. Each dumping plate 21 is preferably provided with one or more depending cam plates 24., cach of which engages a roller 25 at the rear end of a rack bar 26. The bars 26 are mounted to slide in bearings in the frame of thestoker and they are engaged by pinions 27 on a shaft 28 extending transversely of the Stoker. By manual movement of the shaft 28, the racks 26 may be moved forward or rearward` and the dumping plates may be thus moved from the full line -position shown in Fig. 2 to the dotted line position therein.

The upper surface of each dumping plate 21 extends forward beyond the axisof the shaft 22, as clearly indicated in Fig. 2. With this construction, it will be evldent that each dumping plate 21, as it is swung downward, acts as a cam against one or more of the projections 20 to raise the overfeed grates 13 to the dotted line position shown in Fig. 2. v

'Such upward movement of the overfeed grates is effective to revent rearward movement or discharge o the fuel from the retorts over the grates13 while the dumping plates are lowered. It is thus possible .to remove the ash and refuse from the dumping plates without at the same time causing a loss of good fuel which might otherwise escape over the grates 13.

It is sometimes desirable that the grates 13 should receive a slight angularfmovement during the operation of the stoker, in addition vtothe forward and rearward reciprocating movement thereof. When such an lar movement is desired, it may be rea. 'ly obtained'by positioning the dumping plates 21 at a slight angle either above or below the horizontal. In either case, the grates 13` as they reci rocate, will be slightly raised and lowered y their sliding contact with the t inclined surface of the dumping plates, giving a slight additional agitation of the fuel at the rear of the retort.

The plates 21 may be provided with slots or openings 3l in the rear portion thereof through which air from the ash pit may work upward through the refuse to assist in consuming any combustible material remaining therein.

In Fig. l, I have shown a modified structure in which dumping plates 35 are provided with cam portions 36 supporting the grates 37. As the grates are moved forward and rearward, the cam portions 36 supply vertical components of movement, and when swung downward to dumping position the ates are raised to hold the fuel asv in the orm previously described.

Having thus described my invention andl the advantages thereof, it will be seen that I have rovided an extremely simple construction y which rearward movement of the fuel over the grates 13 is automatically prevented during the dumping of the plates 21,

and by means of which supplemental agitation of the fuel may be obtained if desired. It will also be evident that changes and modifications can be' made in my invention by those skilled ,in the art within the spirit and scope of m -invention as set forth in the claims, and do not wish to be otherwise limited to the details herein disclosed but- What I claim is :--v 4 1. In a Stoker, amovably mounted overfeed grate, a dumping late, and means to move said dumping .p ate, said dumping late directly engaging said grate and therey raising said grateby direct action thereof to prevent discharge of fuel over said grate when said dumping plate is lowered.

2. In a Stoker, a lurality of retorts having side walls' mova le forwardly and rearwardly in said stokerfair-admitting overfeed gratos mounted at the rear of said retorts and actuated to move forward and rearward with said walls, and dumping lates positioned at the rear'of said over eed gratos, said dumping plates-engaging said grates and cooperating with said grates to give a vertical component of movement to said overfeed grates simultaneous with and in addition to said forward and rearward movement of said grates.

3. In a Stoker, a plurality of retorts having movable side walls, grates pivotally mounted and'connected to said movable walls to move therewith, dumping plates supporting the rearward ends of said grates, and means` to dump said plates, said plates being formed to raise said grates as said plates are dumped, thereby preventingthe discharge of fuel over said grates.

4. In a stoker, a plurality of retorts having movable side walls, grates pivotally mounted and connected to said movable walls to move therewith, dumping plates supporting the rearward ends of said gratos, and means to dump said lates, said plates engaging portions of sai grates and swinging said grates upward as said plates are lowered.

5. In a stoker, a plurality of retorts having side walls movable forwardly and rearwardly in said stoker, air-admitting overfeed grates ,mounted at the .rear of said retorts and actuated to move forward and rearward with said walls, dumpin plates positioned at the rear of said overfee grates,

said dumping plates engaging said gratos and cooperating with said grates to .give a vertical component of movement to said overfeed grates simultaneous with and'in addition to said forward and rearward movement of said grates, and means to change the angular position of. rest of said dumping plates, thereby varying the extent of vertical movement of said grates.

6. In a Stoker, a retort, an overfeed grate mounted at the rear of said retort, means ,to reciprocate said grate forward and rearward in said Stoker, a dumping plate, and mans to move said dumpin plate to raised and lowered positions, saidl'r plate having a cam portion supporting the rear part of said grate and imparting additional movements to said.

` grate as said grate is reciprocated.

In testimony whereof I have hereunto affixed my signature.

ROBERT S. RILEY. 

